The present invention relates to zippered bags, and more particularly, to a zipper profile used in connection with such bags. It is known to use airtight plastic bags and containers to conveniently store bulky materials such as clothing and bedding. Airtight plastic bags are also known to store food and other materials. Examples of such airtight bags are disclosed in U.S. Pat. Nos. 6,357,915; 6,116,781; and 5,480,030, each of which is incorporated herein by reference. Airtight bags allow air to be removed from bulky items such as comforters and sweaters, and the bag sealed to essentially “shrink” the items stored inside the bag. Air can be compressed from the contents, for example, by rolling the contents prior to closing the bag. The bags may also have a one-way valve to which a vacuum attachment can be affixed to evacuate the air from inside the bag using a conventional household vacuum cleaner or a specially designed pump. Removal of air reduces the amount of space necessary to store the items. When food items are stored, preventing air from reaching the food items can prolong their freshness. Air can be squeezed or pumped from the food storage bag prior to closing. The above bags are typically made of materials such as bi-axial layers of nylon and polyethylene to make the bags air and moisture impermeable, and hold the airtight vacuum seal.
The bags have a zippered closure at the mouth of the bag. Examples of zippered closures are disclosed in U.S. Pat. Nos. 6,033,113 to Anderson, and 6,059,457 to Sprehe et al, both of which are incorporated by reference herein. The zippered closure is typically made of plastic, and has a pair of zipper profiles that interlock to form the zippered closure.
Often associated with the zippered closure is a slider that facilitates sealing the zippered closure. The slider closes and can open the zippered closure. Examples of sliders include those disclosed in U.S. Pat. Nos. 6,306,071; 6,287,001; 6,264,366; 6,247,844; 5,950,285; 5,924,173; 5,836,056; 5,442,837; 5,161,286; 5,131,121; 5,088,971; and 5,067,208.
It is well known in the art of bagmaking to crush the ends of the zippered closures. The bags are longitudinally cut at the crushed sections or “end stomps” to create separate bags which typically are formed in a continuous web. When the zippered closure ends are crushed, the zippered closure is melted and deformed in such areas. The act of crushing results in voids in the transition zone between the end stomp and the intact zipper profile through which air can travel. Thus, the bags will not be airtight.
As disclosed in Sprehe, typical zippers include flanges that extend from the zipper profile that secure the zippers profiles to the bag film, and ostensibly to provide excess plastic material to fill any voids during crushing. The use of flanges results in several problems. Because the flanges are relatively thin, the bag is attached at a weak area of the profile. Moreover, the gap between the flanges needs to be filled when crushing the ends. The flanges disclosed in Sprehe and Anderson, and the filler disclosed in Anderson also result in increases in the zipper cost. The zipper profile of the present invention solves these and other problems.